Valve

ABSTRACT

A valve comprising a body and a plug is disclosed. The body has a pair of ports and a tubular structure having a side wall and an open end and defining interiorly a first subchamber communicating with one port. The wall has an opening. The body defines a second subchamber communicating with the other port, extending around the wall and beyond the end to communicate with the end and the opening. The plug has an opening, is mounted to the structure and telescopes between first and second positions. At the second position, the plug is disposed at least partly in the second subchamber and the valve defines, between the ports: a first flow path through the wall opening; and a second flow path through the open end of the structure, via the plug opening. At the first position, the plug and structure restrict flow through the first and second paths.

FIELD OF THE INVENTION

The present invention generally relates to a valve for controlling fluidflow.

BACKGROUND OF THE INVENTION

In automobile engines or fuel cell stacks, a fluid or coolant istypically used to carry excess heat from the engine to the radiator.Usually, such coolant is continuously circulated by a pump, through theengine/ stack until its temperature exceeds a predetermined level, atwhich point a portion of the flow is routed through the radiator. Theflow is continuously adjusted in an attempt to maintain the temperatureof the engine/stack within a desired range. In the context of internalcombustion engines, this is often done via a valve that is actuated by awax motor that is immersed in the flow.

In a known prior art fluid circuit, the radiator and a closure valve areconnected in series in the coolant circuit, and a bypass circuit isconnected in parallel across the radiator and closure valve. The valveis configured so as to block the flow of coolant through the radiatorwhen the valve is closed. When the valve is closed, the coolantcontinues to circulate through the engine via the bypass circuit. Adisadvantage associated with this configuration is that the bypass flowpath remains open at all times such that a substantial portion of theflow of coolant always bypasses the radiator, even if maximum cooling iscalled for.

Various valves form part of the prior art.

To avoid the problems associated with a permanent bypass flow, thesevalves provide for the selection between a heat exchanging fluidcircuit, which passes through the radiator, and a non-heat exchangingfluid circuit, which short circuits or bypasses the radiator. (In thecontext of traditional internal combustion engine vehicles, the bypassloop is often the heater core circuit, which is technically also a heatexchanging fluid circuit, so that there is always coolant flow throughthe heater core. The option to provide or not provide heat to thepassenger cabin is achieved via manual or vacuum operated valve controlof ducting of the air flow through or around the heater core.).

However, known valves are either relatively expensive, relativelynon-robust, or have relatively poor flow characteristics.

SUMMARY OF THE INVENTION

A valve for use with a fluid forms one aspect of the invention. Thisvalve comprises a valve body and a plug. The valve body has: a pair ofspaced-apart flow ports; an interior chamber; an interior wall at leastpartially dividing the interior chamber into a first subchamber to whichone of the flow port leads and a second subchamber to which the other ofthe flow ports leads, the interior wall having a wall openingtherethrough leading between the first subchamber and the secondsubchamber; an interior opening providing for communication between thefirst subchamber and the second subchamber; and a further flow portspaced-apart from the interior opening along an axis. The plug has aplug opening therein, and is axially moveable in the interior chamberbetween and a first position and a second position. At the secondposition, the plug seals the further flow port and the valve defines: afirst flow path between the spaced-apart flow ports, through the wallopening; and a second flow path between the spaced-apart flow ports,through the interior opening and the plug opening. At the firstposition, the interior wall seals the plug opening and the plug sealsthe interior opening and the wall opening, thereby to at leastsubstantially isolate the first subchamber from the second subchamberand channel the flow through a further flow path for said fluid throughthe valve body between the other of the flow ports and the further flowport.

According to another aspect of the invention, the first flow path andthe second flow path can collectively define a primary flow path, andthe primary flow path and the further flow path can each be free ofsubstantial constrictions over their respective lengths.

A valve for use with a fluid forms yet another aspect of the invention.This valve comprises a valve body and a plug. The valve body has a pairof spaced-apart flow ports and includes a tubular structure. The tubularstructure has a side wall and an open end and defines interiorly a firstsubchamber in fluid communication with one of the flow ports. The wallhas a wall opening therethrough. The body further defines a secondsubchamber in fluid communication with the other of the flow ports, thesecond subchamber extending around the side wall and extending beyondthe open end to further fluidly communicate with the open end and thewall opening, The plug has a plug opening and is mounted to the tubularstructure for telescopic movement between a first position and a secondposition. At the second position, the plug is disposed at least in partin the second subchamber and the valve defines: a first flow pathbetween the flow ports through the wall opening; and a second flow pathbetween the flow ports through the open end of the tubular structure andthe plug opening. At the first position, the plug and tubular structureinteract to restrict flow through the first flow path and the secondflow path.

The present invention permits the construction of a relatively low cost,relatively robust valve, which exhibits relatively good flowcharacteristics Other advantages, features and characteristics of thepresent invention, as well as methods of operation and functions of therelated elements of the structure, and the combination of parts andeconomies of manufacture, will become more apparent upon considerationof the following detailed description and the appended claims withreference to the accompanying drawings, the latter being brieflydescribed hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a valve according to one embodiment ofthe invention;

FIG. 2 is an exploded perspective view of the structure of FIG. 1;

FIG. 3 is a view of encircled area 3 of FIG. 2;

FIG. 4 is a top view of the structure of FIG. 3;

FIG. 5 is a section along 5-5 of FIG. 4,

FIG. 6 is an enlarged view of encircled area 6 of FIG. 2;

FIG. 7 is a perspective view of the structure of FIG. 6, from anothervantage point;

FIG. 8 is a side view of the structure of FIG. 6;

FIG. 9 is an enlarged view of encircled area 9 of FIG. 2;

FIG. 10 is a perspective view of the structure of FIG. 9, from anothervantage point;

FIG. 11 is a perspective view of the structure of FIG. 9, from anothervantage point;

FIG. 12 is a perspective view of the structure of FIG. 9, from anothervantage point;

FIG. 13A is a view similar to FIG. 5 of the valve of FIG. 1, showing awax motor in a fully retracted arrangement and the valve in a bypassconfiguration thereof;

FIG. 13B is a view similar to FIG. 13A, showing the wax motor in apartially extended arrangement and the valve in a flowthroughconfiguration thereof;

FIG. 13C is a view similar to FIG. 13B, showing the wax motor in a fullyextended arrangement and the valve in the flowthrough configurationthereof;

FIG. 14 is a schematic view of a valve similar to the valve of FIG. 1 inuse in an engine block casting;

FIG. 15 is a schematic view of a valve similar to the valve of FIG. 1 inuse in a radiator;

FIG. 16 is a view, similar to FIG. 13A, of a valve according to a secondembodiment of the invention;

FIG. 17 is a view, similar to FIG. 13A, of a valve according to a thirdembodiment of the invention;

FIG. 18 is a view, similar to FIG. 13A, of a valve according to a fourthembodiment of the invention;

FIG. 19 is a view, similar to FIG. 13A, of a valve according to a fifthembodiment of the invention;

FIG. 20 is a phantom view of the valve of FIG. 1, showing a blacklinedvolume which represents the extent to which the flow ports are directlyaligned;

FIG. 21 is a view, similar to FIG. 19, of a valve according to a sixthembodiment of the invention;

FIG. 22 is a view, similar to FIG. 19, of a valve according to a seventhembodiment of the invention;

FIG. 23 is a perspective view of a cartridge structure according to aseventh embodiment of the invention;

FIG. 24 is a cross-sectional view of the structure of FIG. 23;

FIG. 25 is a schematic view of a valve according to an embodiment of thepresent invention in a first exemplary use;

FIG. 26 is a view similar to FIG. 25 of a second exemplary use;

FIG. 27 is a perspective view of an alternative embodiment of thestructure of FIG. 11, as present in FIGS. 23, 24;

FIG. 28 is a side view of an alternative embodiment of the structure ofFIG. 6, as present in FIGS. 23, 24, in use with the structure of FIG.27;

FIG. 29 is a perspective view of a further alternative embodiment of thestructure of FIG. 6; and

FIG. 30 is a perspective view of a yet further alternative embodiment ofthe structure of FIG. 6.

DETAILED DESCRIPTION

With general reference to FIGS. 1-13C, a first embodiment of the presentinvention, a valve for use with a fluid such as engine coolant, isillustrated and is designated by the general reference numeral 20. Withreference to FIG. 2, the valve 20 comprises a housing 22 and a valvecartridge 24. This housing 22 is of aluminum and includes a centralportion 26 defining an open receptacle and three spigots 28,30,32extending therefrom in a tee arrangement, each leading into the openreceptacle. Two of the spigots 28,30 are substantially parallel andopposed to one another. The third spigot 32 extends transversely to theothers. The inner surface 34 of the receptacle has a peripheral groove36 extending therearound. The valve cartridge 24 includes an aluminuminsert 38, an aluminum plug 40, an actuator 42 and a rubber O-ring 44.The insert 38 has a peripheral groove 48 which receives the O-ring 44and can be fitted in the receptacle 26 and secured in place with aspring clip 50 which interfits in groove 36, as indicated in FIG. 13A.So secured, the O-ring 44 sealingly engages each of the insert 38 andthe inner surface 34 of the receptacle 26, to seal the insert 38 andhousing 22 to one another, such that the insert 38, the O-ring 44 andthe housing 22 together define a valve body.

With reference to FIG. 13A, the valve body has a pair of flow ports52,54, an interior surface 56, an axis X-X, an interior wall 58, afurther port 60, a first valve seat 62 and a second valve seat 64. Theflow ports 52,54 are spaced-apart from, substantially opposed to andsubstantially aligned with one another, and communicate one each withthe parallel spigots 28,30. Flow ports 52,54 are each orientatedsubstantially transverse to axis X-X. In this disclosure and in theappended claims, “substantial alignment” of the flow ports 52,54 meansthat, if one were to project the flow ports across the valve bodyparallel to their respective flow directions, the projections wouldintersect to a substantial extent, as indicated by FIG. 20, wherein thevalve is shown in phantom and the volume of intersection is indicated bythe blacklined volume.

The interior surface 56 defines an interior chamber 66 of the valve bodywhich is disposed between the flow ports 52,54 and communicatestherewith. The axis X-X is aligned with the third spigot 32, andorientated transversely to a flowthrough direction Y-Y with which theflow ports 52,54 are substantially aligned. The interior wall 58: is agenerally semi-cylindrical structure centred about the axis X-X; extendsaxially, partially across the interior chamber 66; defines, incombination with the interior surface 56, an interior opening 68; andhas a wall opening 70 therethrough. Wall opening 70 is opposed to andaligned with flow port 52, i.e. wall opening 70 and flow port 52 presentto one another. Flow port 54 and wall opening 70 are aligned, i.e. ifone were to project flow port 54 parallel to its flow direction (notshown), the projection would intersect with wall opening 70 to asubstantial extent. The interior wall 58, in combination with portionsof the valve body, notionally defines a tubular structure, in which theinterior opening 68 defines an open end and of which the interior wall58 defines a side wall.

The interior opening 68 provides for communication between a firstsubchamber 72 of the interior chamber 66 to which one 52 of the flowports leads and a second subchamber 74 of the interior chamber 66 towhich the other 54 of the flow ports leads. The second subchamber 74extends partially around the side wall and beyond the open end of thetubular structure described hereinbefore. The wall opening 70 in theinterior wall 58 also leads between the first 72 and second 74subchambers. Both the interior wall 58 and the wall opening 70 thereofeach circumscribe an angle of about 180°. The further port 60 providesfor communication between second subchamber 74 and third spigot 32. Thefirst valve seat 62 surrounds the further flow port 60 and is defined bythe interior surface 56 of the valve. The second valve seat 64 surroundsthe interior opening 68, is axially spaced from the first valve seat 62and is defined by the interior surface 56 and by the end of the interiorwall 58.

As best seen in FIGS. 6-8, the plug 40 has a circular base portion 76and a semi-cylindrical sidewall portion 78 extending from the baseportion 76. Sidewall portion 78 has a bisected plug opening 80 therein,and each of the side portion 78 and the plug opening 80 circumscribe anangle of about 180°. In FIG. 13A, the plug 40 is shown in a firstposition in the interior chamber 66. So positioned, base portion 76 andside portion 78 are both centred about the axis X-X, such that sideportion 78 is concentric with the interior wall 58, the interior wall 58is nested within plug 40, the base portion 76 is seated on the secondvalve seat 64, the interior wall 58 overlies the plug opening 80 and theside portion 78 overlies the wall opening 70 to at least substantiallyisolate the first subchamber 72 of the interior chamber 66 from thesecond subchamber 74. This defines an arcuate (or bypass, when the valveis used as a bypass valve) flow configuration of the valve 20, whereatthe valve 20 defines a further flow path B-B through the valve bodybetween spigots 30,32 via flow port 54 and further port 60.

The actuator 42 is for axially moving the plug 40 in the interiorchamber between the first position shown in FIG. 13A and a secondposition shown in FIG. 13B. In the second position of the plug 40, thebase portion 76 is seated on the first valve seat 62, to at leastsubstantially occlude the further port 60. This defines a flowthroughconfiguration of the valve 20, whereat the valve 20 defines a primaryflow path F-F through the valve body between spigots 28,30 via flowports 52,54. In such configuration, it will be observed that the sideportion 78 of the plug 40 and the interior wall 58 are arranged behindone another, to maximize the area through which fluid may flow. Theprimary flow path is a split-flow arrangement, with a first flow pathbetween ports 52,54 being by way of the wall opening 70 and a secondflow path between ports 52,54 being through the open end of the tubularstructure, i.e. interior opening 68 and the plug opening 80. In thisposition of the plug 40, the plug opening 80 and flow port 54 arealigned.

With reference to FIGS. 2, 6-8 and 13B, the actuator 42 shown includes awax motor 82, a frustoconical stainless steel return spring 84, acylindrical stainless steel override spring 86 and an aluminum tubularsleeve 88. The sleeve 88 has annular flanges 90,92 extending around eachend and extends through an opening 98 in the circular base portion 76.The flanges 90,92 provide for the sleeve 88 to be captured by thecircular base portion 76. The wax motor 82 is of a conventional typewhich includes a shell 91 having an enlarged head 89 from which a shaft93 protrudes, the shaft 93 moving in response to thermally-inducedexpansion of the wax-like material (not shown) contained within theshell 91. The motor 82 is fitted in the sleeve 88, and a C-clip 194 issecured thereto, such that enlarged head 89 and the C-clip 194 capturetherebetween the sleeve 88. The shaft 93 projects from the wax motor 82into a socket or recess 94 formed in the insert 38. The return spring 84extends between the sleeve flange 92 which is captured by the C-clip 194and the bypass port 60. The override spring 86 is fitted around thesleeve 88 and extends between the sleeve flange 90 which is captured bythe enlarged head 89 and the base portion 76 of the plug 40.

In operation, when the temperature of the wax in the wax motor 82 isbelow the wax-actuator set point, the wax-like material volume isrelatively low, such that the shaft 93 can fit substantially within theshell 91. Bias provided by the return spring 84 ensures that the shaft93 is positioned within the shell 91 sufficient to enable flange 92 toretain base portion 76 of the plug 40 against the second valve seat 64,as shown in FIG. 13A. This corresponds to a fully retracted arrangementof wax motor 82.

When the temperature of the wax-like material in the motor 82 reaches orexceeds the actuator set point temperature, the wax-like materialexpands. This causes shaft 93 to be partially expelled from the shell91. As the shaft 93 cannot extend through the socket 94, extension ofthe shaft 93 from the shell 91 is accommodated by movement of the shell91, and the sleeve 88 by which it is mechanically captured, away fromthe socket 94. Initially, as the shell 91 moves away from the socket 94,bias provided by the override spring 86 causes the base portion 76 toremain engaged against flange 92 during such movement, such thatmovement of the shell 91 corresponds to movement of the plug 40. In thecourse of such movement, the plug 40 will ultimately reach the secondposition, as shown in FIG. 13B. This corresponds to a partially-extendedarrangement of the wax motor 82. At this point, the base portion 76 ofthe plug 40 is seated against the first valve seat 62, and can move nofurther; if the wax-like material requires further expansion volume,this will be accommodated by movement of the sleeve 88 through theopening 98 in the base portion 76, as shown in FIG. 13C. Thiscorresponds to a fully-extended arrangement of the wax motor 82. Personsof ordinary skill will recognize that this arrangement is advantageous,since the shaft extension in any given wax motor or in a manufacturedbatch thereof can vary. By providing an override spring arrangement, avalve designer can ensure that the valve will move predictably betweenthe first and second positions in response to temperature change, andcan also avoid undue stresses in the valve that might follow ifaccommodation was not made for overextension.

When the temperature of the wax-like material in the wax motor 82 fallsbeneath the set point, the conical return spring 84 will drive the shell91 back over the shaft 93. Until such time as flange 92 of the sleeve 88engages base portion 76, bias provided by override spring 86 willmaintain base portion 76 seated against the first valve seat 62.Expansion of the conical spring 84 beyond that point will result inmovement of the sleeve 88 and plug 40 together, during which movement,the interior wall 58 telescopes into the plug 40. Ultimately, the plug40 returns to the first position, and further movement is arrested byengagement of the base portion 76 with the second valve seat 64.

In one use, the valve of FIG. 1 is used as a bypass valve and deployedin an automobile cooling circuit. In this use (not shown), spigot 30receives a hose (not shown) through which coolant from the engine isreceived, spigot 28 is coupled by a hose to the radiator inlet (neithershown) and the further spigot 32 is coupled by a hose through whichcoolant is delivered to the engine. When the coolant temperature isbelow the wax actuator set point (and wherein the coolant is notsufficiently heated to be required to shed heat), the wax-motor ismaintained in the fully-retracted position, the plug is disposed in thefirst position and the valve is disposed in the bypass configuration,such that most of the coolant follows path B-B back to the engine. Thus,in this use, port 54 is an inlet port and ports 52, 60 are outlet ports.In the bypass configuration, leak paths exist in the seal between thebase portion 76 of the plug 40 and the second valve seat 64, in thejunction between interior portion 58 and side portion 78, in thejunction between sleeve 88 and opening 98 in the base portion 76 and inthe junction between the shell 91 and the sleeve 88. Thus, the wax motor82 is not entirely isolated from the flow, so as to be susceptible toactuation when the flow temperature exceeds the wax set point. When thisoccurs, the plug 40 moves to the second position and the valve assumesthe flowthrough configuration, such that most of the coolant followsflow path F-F through the radiator before being returned to the engine.Again, in this configuration, leak paths will exist, in the seal betweenthe base portion 76 of the plug 40 and the first valve seat 64, in thejunction between interior wall 58 and side portion 78, in the junctionbetween sleeve 88 and opening 98 in the base portion 76 and in thejunction between the shell 91 and sleeve 88.

A similar use is shown schematically in FIG. 14. Herein, a valve 20′similar to that of FIG. 1 but lacking spigots is fitted in an engineblock casting 99, with the flow ports forming part of the coolantcircuit (not shown) from the engine to the radiator and the bypass portcoupled to a circuit (not shown) which bypasses the radiator and returnsto the engine. The operation of this valve 20′ is functionally identicalto the valve 20 and use thereof previously described, and thus is notfurther described herein.

A further use of the valve 20′ of FIG. 14 is shown schematically in FIG.15. Herein the valve 20′ is fitted in a radiator 101, with the flowports forming part of a heat exchanging circuit 103 through whichcoolant is caused to traverse the heat exchanger 101 and shed heatbefore returning to the engine, and the bypass port forming part of acircuit 105 which bypasses the heat-exchanging portion of the radiatorin its return to the engine. Again, the operation of this valve 20′ isfunctionally identical to the valve 20 and uses thereof previouslydescribed, and thus is not further described herein.

It is notable that in each of the valves and uses described, there isfound a cartridge 24 which contains all of the moving parts of thevalve, so as to advantageously permit ready system assembly, or removaland replacement as required. The present valve has also been found tohave relatively low pressure losses in use, which is known to beadvantageous in the automotive field since it permits relatively smallerand lighter pumps to be utilized, with commensurate savings inautomobile cost and weight and with commensurate improvements in termsof energy efficiency.

Without intending to be bound by theory, it is believed that theadvantageous flow characteristics of the present valve derive from theshape of the valve and its components. Notable in this regard, theprimary flow path is substantially parallel to the flows leading to andfrom the valve. Further, each of the primary and further flow paths isfree of substantial constrictions over their respective lengths owing,inter alia, to the relatively large volume of the second subchamber 74which the flow traverses in the arcuate or bypass configuration of thevalve, and to the relatively large area of openings 70,80 (similar insize to the area of each of the flow and further ports 52,54,60) throughwhich the flow traverses in the flowthrough configuration of the valve.Additionally of note is the shape of the second subchamber 74 of theinterior chamber, specifically, the upper portion thereof having aC-shaped or arcuate cross-section, which permits the flow entering fromflow port 54 to spread out, around the side wall 78/interior wall 58,before passing under the base portion 76 and exiting the valve throughthe port 60.

Various other embodiments of the valve are shown in FIGS. 16-18. Thesevalves are similar in function to the valve of FIGS. 1-13C, but whereasthe valve of FIGS. 1-13C employs a wax motor to drive the plug betweenthe first and second positions, these valves employ other forms ofactuators to accomplish the same function. FIG. 16 shows a valve 20″wherein the plug 40 has a threaded post 100 axially extending therefromwhich is received by an internally-threaded driveshaft 102 coupled to amotor 104. The motor 104 can rotate the drive shaft 102, which rotatesabout the threaded post 100, so as to result in axial movement of thepost 100 and consequent movement of the plug 40 between the first andsecond positions. FIG. 17 shows a valve 20′″ wherein a rack 106 extendsfrom the plug 40, a pinion 108 is in mesh with the rack 106 and a motor110 is drivingly coupled to the pinion 108. Herein, the motor 110rotates the pinion 108 which drives the rack 106 axially to move theplug 40 between the first and second positions. FIG. 18 shows yetanother valve 20″″ wherein a cam follower 112 is coupled to the plug 40,a cam 114 is engaged with the cam follower and a stepper motor 116 iscoupled to the cam 114. Herein, the stepper motor 116 rotates the cam114 to engage the cam follower 112 and drive the plug axially betweenthe first and second positions. In each of these cases, some form ofexternal sensor or control would be used to trigger the movement of theplug. As the construction of actuators, sensors and controls of thistype is routine to persons of ordinary skill in the art, and as thevalves 20″, 20′″, 20″″ operate in a manner substantially similar tovalves 20 and 20′, further description as to their respectiveconstruction and operation is neither necessary nor provided.

A further possible modification is shown in the valve 20′″″ of FIG. 21which is similar to the valve of FIG. 18, but also includes a tubularskirt 120 which extends from the plug and telescopes into the furtherport. Herein, bypass flow through the further port is restricted, byvirtue of its need to pass through holes 122 defined in the skirt 120.By changing the shapes/sizes of holes 122, the flow characteristics ofthis valve can be modified at different points during movement betweenthe first and second positions, to allow flow to be metered orlinearized. In addition to the metering functionality, the skirtprovides prealignment of the plug, which can assist in sealing in theflowthrough position, avoid binding, avoid deformation of the shaft andimprove uniformity of the bypass flow stream to, inter alia, balanceinterior pressures in the valve and improve sealing in the bypassposition. Persons of ordinary skill in the art will readily appreciatethat pressures that will be experienced in the valve interior in use atvarious positions between full bypass and no bypass will be a functionof the flow resistance in the bypass and flowthrough circuits. In theevent of flow resistance in the circuits that is significantlyunbalanced, which would otherwise tends to drive substantially all flowto the lower pressure circuit, even if the valve is opened only partlythereto, a skirt can be used to balance the aggregate pressure drop,inclusive of the valve and the circuits, such that flow is directedtowards the higher pressure circuit as a relatively more linear functionof the position of the plug. Although circular “holes” disposed whollywithin the skirt and equally radially-spaced are specifically shown inFIG. 21, it should be understood that the “holes” (i) need not becircular and could be triangular, rectangular, oval, etc.; (ii) could“bridge” the edge of the skirt, i.e. the skirt could have a toothed (asper the embodiment 500 shown in FIG. 29), scalloped (as per theembodiment 600 shown in FIG. 30) or otherwise irregular end for flowproportioning, and (iii) the holes, teeth, scallops or irregularities inthe skirt could be spaced otherwise than radially-equally, for example,the holes, teeth, scallops or irregularities could be concentrated inone area, for flow contouring purposes.

A yet further modification is shown in the modified valve 20″″″ of FIG.22. This valve is substantially similar to the valve of FIG. 18, butlacks the further “bypass” port.

FIGS. 23 and 24 show the cartridge portion 200 of a further embodimentof the valve of the present invention. This cartridge portion 200 bearssome similarity to the valve cartridge of FIG. 16, particularly in thateach employ a rotating element to secure linear motion of the plug 40.However, whereas in the structure of FIG. 16, plug 40 has anexternally-threaded post 100 and the shaft 102 rotates and isinternally-threaded, in FIGS. 23, 24, an externally threaded shaft 102′is provided, which engages within an externally threaded shaft extension206; the extension 206, in turn, is engaged within an internallythreaded post 100′. The threaded shaft 102′ does not rotate, and indeed,a restraint device 220 in the form of a key/keyway arrangement isprovided, to arrest rotation of shaft 102′, but rather, is threadinglyengaged by an internally-threaded rotor 230 which rotates under magneticcontrol of a stator coil 218 forming part of the stepper motor 216.Upper and lower bearings 240, retain the rotor 230 in position whilepermitting free rotation. As a further modification, the cartridge 200includes a biasing spring 204, for urging the plug 40 towards theflowthrough position. As well, the sidewall portion 78 is adapted forbetter sealing of the wall opening 70, via axially-spaced spaced apartedges 78A, 78B which engage, in the bypass position of the plug 40,respectively, with a lip 58A formed on the interior wall 58 and a groove202 formed in the valve body. Axial grooves 400 are also formed in thevalve body, in which the sidewall portion 78 slides during movementbetween the bypass and flowthrough positions, and an upstanding lip 205is formed on the base portion 76 which engages groove 207 formed in thevalve body in the bypass position of the plug 40. In this embodiment,when signal to the valve is lost, i.e. when the stepper motor 216 losespower (and the rotor 230 becomes freely movable) the spring 204 reliablyurges the plug 40 to the flowthrough position, via rotation of the rotor230. However, it will be appreciated that movement of the spring of thisembodiment to the position of the spring shown in FIGS. 17, 18, coupledwith suitable modifications to the stepper motor size and step ratio,rotor and shaft thread pitch and spring size, to address forces exertedon the plug [which should be understood to vary, inter alia, with fluidflow, backpressure and plug position in the valve], can produce anembodiment wherein the spring 204 reliably urges the plug 40 to thebypass position in the event of signal loss. The manner in which suchmodifications can be carried out is a matter of routine to persons ofordinary skill in the art, and as such, is not described herein indetail. As a variation of the foregoing, it has been found that valvesaccording to the present invention can be created that move reliably toone port (i.e. bypass or flowthrough configuration, as desired) only inlow flow conditions. Thus, in the event that signal or power is lost tothe stepper motor, but the pump remains at full power, the valve doesnot immediately assume the failsafe position, which could result in“water hammer” damage. To achieve this functionality, the appropriatebalance must be struck between (i) spring bias and stepper staticfriction; and (ii) hydraulic forces associated with differentialpressure between the first and second subchambers. The manner in whichsuch modifications can be carried out, which may but need not involvethe use of a skirt as described herein, is a matter of routine topersons of ordinary skill in the art, and as such, is not describedherein in detail.

A valve using the cartridge of FIGS. 23, 24 can be used, for example, inthe manner contemplated by FIG. 15, i.e. as a radiator bypass valve foran internal combustion engine. However, as this valve can be produced toembody both (i) proportionality, i.e. incremental selectivity betweenflowthrough and bypass; and (ii) a fail-safe, this valve could also beemployed, in combination with (not shown) a variable speed pump and fan,to conspicuous advantage in fuel cell applications, wherein precisecontrol of stack temperature under a range of duty cycles is criticalfor proper functioning.

FIG. 25 schematically shows such a valve 300 in an inlet divertingconfiguration for a coolant circuit. In this configuration, the valve300 has one inlet port and two outlet ports. The coolant flow, driven bythe pump 320, enters the valve 300 from the fuel cell stack 302 or otherheat source and is split into the outlet ports going towards the bypassline 304 and radiator line 306. This valve diverts the inlet stream toeither the radiator 316, the bypass line 304 or a combination thereof,if the plug is caused to assume a position intermediate the bypass andflowthrough position.

FIG. 26 schematically shows such a valve 300 in an inlet mixingconfiguration, in which the valve 300 has two inlet ports and one outletport. The inlet fluid flows entering the valve from the bypass line 304and the radiator line 306 are joined together and mixed into the valveoutlet stream, with the valve controlling the relative amount of flowthrough each of the radiator 316 and bypass 304.

In either configuration, the valve, in combination with pump speed andradiator fan speed, allows the temperature of the heat source to becontrolled by diverting flow between radiator and bypass loop.

The availability of proportionality in valve operation not only permitsfine adjustment to be made to the flow distribution, for precise tuningof temperatures, but also can be utilized to avoid valve oscillation. Byway of explanation, during cold conditions, if all flow were directed tobypass the heat exchanger, the coolant in the heat exchanger would stayvery cold. At that point, if the valve were then to reconfigure tocompletely arrest bypass flow, a large slug of cold coolant would enterthe heat exchanger. This would have an impact on the operation of anyfuel cell or other temperature sensitive equipment in the circuit, andcould also trigger an immediate reversion of the valve to the bypassconfiguration i.e. valve oscillation [i.e. sensors could detect the lowtemperature coolant slug and construe this as a need for heating]. Toavoid this phenomenon, the valve of FIG. 24 could be operated so as tomove incrementally between flow-through and bypass configurations, so asto avoid the contemplated cold-slug. Depending upon the specifics of theparticular application, including but not limited to the pressure dropacross the bypass circuit and the heat exchange circuit and theviscosity of the coolant, this functionality may be further enhancedthrough the use of a calibrated leak, for example, a hole of apredetermined size (not shown) through the base portion 76 or other ofthe components of the valve, and/or through the use of a skirt 120 ofthe general type described with reference to FIG. 21.

The fail-safe functionality attainable by, inter alia, valves accordingto FIG. 24, permits the circuit to be adjusted such that, in the eventof signal loss to the stepper motor, or power failure to the steppermotor, the valve automatically reverts to a configuration providingmaximum flow to the radiator, to avoid overheating of the fuel cellstack and the associated damage that would cause.

Whereas numerous embodiments and uses of the valve have been hereinshown in described, it will be understood that various modifications canbe made.

For example, whereas the valve is herein sometimes shown and illustratedas a bypass valve, wherein an input or inlet flow is directed to one oftwo outputs or outlets, it will be emphasized that the valve could beused as a mixing valve, wherein flow is selectively received from one oftwo inputs and delivered to a single output. In applications whereinport 52 is deployed as an inlet port, fluid pressure may tend toseparate walls 78,58, and to avoid this, a skirt as shown in FIG. 21 maybe advantageously utilized to stabilize the plug.

As well, whereas the description teaches movement of the plug betweenthe first and second positions, it will be evident that the plug canassume intermediate positions, if flow is to be split, or if a splitflow is to be received. In this case, of course, an actuator capable ofmoving the plug partially between the first and second positions, suchas one of the actuators shown in FIGS. 16-18 and 24, would be used insubstitution for wax motors which, while relatively inexpensive, robustand reliable in comparison to the actuators of FIGS. 16-18 and 24,generally lack proportional responsiveness, i.e. reliably move onlybetween the fully retracted and the fully extended arrangements.

Further, whereas the valves illustrated and described have relativelygood flow characteristics, improvements are contemplated to beachievable through interior contouring or streamlining, as suggested inFIG. 19, wherein a portion 56A of the interior surface 56 has beencontoured for flow conditioning.

Yet further, whereas the valve of FIGS. 1-13C is indicated to beconstructed of steel, aluminum and rubber, it will be evident that othermaterials, such as plastics, could readily be employed.

Additionally, although the valves shown and described herein areindicated to be of a cartridge type, so as to permit [[for eg]] readyremoval and replacement of the moving parts of the valve in the event offailure or excess wear, it will be evident that a cartridge-typeconstruction need not be employed.

Moreover, whereas the plug opening shown and described is indicated tobe bisected, it will be evident that this is not necessary. The plugopening could equally be defined by a single aperture, or by three ormore apertures, and the apertures could be shaped, for flow balancing orlinearization purposes in a manner analogous to that described withreference to the skirt 120. The wall opening 70 could similarly beshaped, for the same purposes. Further, whereas the side portion of theplug and the interior portion are herein indicated to besemi-cylindrical and to circumscribe at least about 180°, it is notnecessary and indeed, not always desirable to have perfectsemi-cylindrical shapes. Semi-elliptical cross-sections might, forexample, be employed, if a relatively “flatter” and “wider” valve wasrequired. As well, tapered plugs, i.e. having a side portion thatcorresponds to a section of a frustocone, may be employed in concertwith similarly-shaped wall portions. This would simplify manufacture ofthe valve from molded plastic parts. Sealing can also be improved byproviding a groove 400 as shown in FIG. 27 and FIG. 24: in combinationwith groove 202, as shown in FIG. 24, this groove 400 receives theentire perimeter of the side portion of the plug in close-fittingrelation, to minimize the leak path in this area. Additionally, whereasthe flow ports and wall opening are substantially opposed to one anotheras shown in the illustrations, it should be understood that flow portsneed not be opposed to one another, but could be disposed in angularrelation to one another.

Further, whereas the interior wall is herein shown to partially dividethe interior chamber, it is contemplated that the interior wall couldextend fully across the interior chamber. In this arrangement, the plugmight telescope interiorly into the first subchamber, and some form ofperforation or aperture in the interior wall could be provided, to matewith the plug opening when the plug is at the second position.

Additionally, it should be understood that “seal”, as used in thedisclosure and in the appended claims, does not necessarily contemplatea complete blockage of flow, but rather simply means that the parts inquestion at least cooperate or interact to restrict or arrest flow.

Further, whereas it is described hereinbefore that the value of FIG. 24has a fully bypass failsafe configuration, it should be emphasized thatvalves according to the invention can be configured to assume eitherfull bypass or no bypass in the event of signal loss. As well, whereasfail-safe functionality is described with particularity in the contextof the embodiment of FIG. 24, it should also be understood that, withsuitable modifications to thread pitch and the like, the samefunctionality can be provided in the embodiment of FIG. 16. As well,valves according to the present invention can employ electronic linearactuators, and fail-safe functionality can also be provided therein.

Similarly, although application to automobile and vehicular applicationsis described above, the invention may also be applied to other internalcombustion engine or fuel cell stack engine applications, such asstationary power generators.

In view of the foregoing, it should be understood that the invention islimited only by the claims appended hereto, purposively construed.

1. A valve for use with a fluid, said valve comprising: a valve bodyhaving: a pair of spaced-apart flow ports; an interior chamber; aninterior wall at least partially dividing the interior chamber into afirst subchamber to which one of the flow port leads and a secondsubchamber to which the other of the flow ports leads, the interior wallhaving a wall opening therethrough leading between the first subchamberand the second subchamber; an interior opening providing forcommunication between the first subchamber and the second subchamber;and a further flow port spaced-apart from the interior opening along anaxis; and a plug having a plug opening therein, the plug being axiallymoveable in the interior chamber between and a first position and asecond position, wherein at the second position, the plug seals thefurther flow port and the valve defines: a first flow path between thespaced-apart flow ports, through the wall opening; and a second flowpath between the spaced-apart flow ports, through the interior openingand the plug opening, and at the first position, the interior wall sealsthe plug opening and the plug seals the interior opening and the wallopening, thereby to at least substantially isolate the first subchamberfrom the second subchamber and to channel the flow through a furtherflow path for said fluid through the valve body between the other of theflow ports and the further flow port.
 2. A valve according to claim 1,wherein the spaced-apart flow ports are each orientated transverse tothe axis.
 3. A valve according to claim 1, wherein the first flow pathand the second flow path collectively define a primary flow path, andwherein the primary flow path and the further flow path are each free ofsubstantial constrictions over their respective lengths.
 4. A valveaccording to claim 1, wherein the valve body has a first valve seatsurrounding the further port and against which the plug is seated in thesecond position thereof; and a second valve seat surrounding theinterior opening, axially spaced from the first valve seat and againstwhich the plug is seated in the first position thereof.
 5. A valveaccording to claim 1, further comprising an actuator for moving the plugbetween the first position and the second position.
 6. A valve accordingto claim 1, further comprising an actuator for moving the plug betweenthe first position and the second position in response to thetemperature of the fluid.
 7. A valve according to claim 1, wherein theinterior wall telescopes into the plug during movement of the plug fromthe second position to the first position.
 8. A valve according to claim1, wherein the interior wall extends axially.
 9. A valve according toclaim 1, wherein the interior wall is semi-cylindrical and the plug hasa semi-cylindrical sidewall concentric therewith.
 10. A valve accordingto claim 9, wherein the plug opening and the wall opening eachcircumscribe an angle of at least about 180°.
 11. A valve according toclaim 1, wherein the spaced-apart flow ports are substantially alignedwith and opposed to one another.
 12. A valve according to claim 1,wherein the one flow port and the wall opening are substantially opposedto one another.
 13. A valve according to claim 1, wherein the other flowport and the wall opening are substantially aligned with one another.14. A valve according to claim 1, wherein the one of the flow ports isan outlet port and the other of the flow ports is an inlet port.
 15. Avalve for use with a fluid, said valve comprising: a valve body having apair of spaced-apart flow ports, said valve body including a tubularstructure having a side wall and an open end, the tubular structuredefining interiorly a first subchamber in fluid communication with oneof the flow ports and the wall having a wall opening therethrough; anddefining a second subchamber in fluid communication with the other ofthe flow ports, the second subchamber extending around the side wall andextending beyond the open end to further fluidly communicate with theopen end and the wall opening, a plug having a plug opening and beingmounted to the tubular structure for telescopic movement between a firstposition and a second position wherein: at the second position, the plugis disposed at least in part in the second subchamber and the valvedefines: a first flow path between the flow ports through the wallopening; and a second flow path between the flow ports through the openend of the tubular structure and the plug opening; and at the firstposition, the plug and tubular structure interact to restrict flowthrough the first flow path and the second flow path.
 16. A valveaccording to claim 15, wherein the tubular structure is substantiallycylindrical, the second subchamber extends partially around the tubularstructure and the plug has a semi-cylindrical sidewall substantiallyconcentric with the tubular structure.
 17. A valve according to claim16, wherein the plug opening and the wall opening each circumscribe anangle of at least about 180°.
 18. A valve according to claim 15, whereinthe tubular structure telescopes into the plug during movement of theplug from the second position to the first position.
 19. A valveaccording to claim 15, wherein the one flow port and the wall openingare substantially opposed to one another.
 20. A valve according to claim15, wherein the other flow port and the wall opening are substantiallyaligned with one another.
 21. A valve according to claim 15, wherein:the valve body has a further flow port spaced-apart from the open end ofthe tubular structure along an axis; the plug moves axially between thefirst position and the second position; at the second position, the plugseals the further flow port; and at the first position of the plug, thevalve defines a further flow path for said fluid through the valve bodybetween the other of the flow ports and the further flow port.
 22. Avalve according to claim 15, wherein the actuator comprises anelectrical stepper motor and is adapted for incremental movement of theplug between the first position and the second position.
 23. A valveaccording to claim 22, further comprising a biasing spring which urgesthe plug to one of the first position and the second position when thestepper motor loses electrical power.
 24. A valve according to claim 22,further comprising a spring for urging the plug to one of the firstposition and the second position and wherein the valve is adapted suchthat the spring moves the plug to said one of the first position and thesecond position when the stepper motor loses electrical power and theflow rate through the valve is sufficiently low to avoid water hammerdamage.
 25. A valve according to claim 15, further comprising a skirtwhich extends from the plug into the further port.
 26. A valve accordingto claim 25, wherein the skirt is tubular and telescopes into and out ofthe port during movement of the plug between the first position andsecond position.
 27. A valve according to claim 25, wherein the skirtprojects into the port when the plug is in the first position and thesecond position, to stabilize the plug against binding.
 28. A valveaccording to claim 25, wherein, in use, the skirt balances the pressuredrop between a first circuit which includes the first flow path and asecond circuit which includes the second flow path such that flow isshifted between the first circuit and the second circuit as asubstantially linear function of the position of the plug.